feat(pm/wiki): enable mobile support

By default, there's no good mobile skin for Mediawiki. You can load
"minerva", which appears to come bundled but not by-default-enabled, but
there's no auto-switching to it when on mobile devices.

The MobileFrontend plugin (as used on Wikipedia) fixes this by using
minerva on mobile devices and a different theme on desktop.

npins/sources.json

···
       "url": null,
       "hash": "sha256-nPShvlf9GizwfzZstFhj4mv3DcHg8leN+zfiv9kETAg="
     },
+    "MobileFrontend": {
+      "type": "Git",
+      "repository": {
+        "type": "Git",
+        "url": "https://gerrit.wikimedia.org/r/mediawiki/extensions/MobileFrontend"
+      },
+      "branch": "REL1_45",
+      "submodules": false,
+      "revision": "2bccb7e19bbe154ac24eae97137ce5396d63339d",
+      "url": null,
+      "hash": "sha256-X4vq7SnGQZMBjDDCv6ZRllnDzJ/QmKoA2REkC/2jm+g="
+    },
     "NamespacePreload": {
       "type": "Git",
       "repository": {

packetmix/systems/teal/wiki.nix

···
       }/share/php/Elastica"; # needed for cirrussearch
       Linter = null;
       Math = null;
+      MobileFrontend = project.inputs.MobileFrontend.src;
       NamespacePreload = project.inputs.NamespacePreload.src;
       Network = "${
         config.services.phpfpm.pools.mediawiki.phpPackage.buildComposerProject {
···
       $wgCargoFileDataColumns[] = 'lastUploadDate';
 
       $wgFixDoubleRedirects = true;
+
+      $wgMFAutodetectMobileView = true;
+      $wgMFEnableMobilePreferences = true;
+      wfLoadSkin( 'MinervaNeue' );
 
       $wgShowExceptionDetails = true;
       $wgDevelopmentWarnings = true;